This invention relates to anchors and more particularly to a system for augmenting the holding capacity of installed deadman type anchors including stakepiles, propellant-embedded anchors, vibrated-in anchors, jetted-in anchors and clumps.
There are frequent problems in anchoring in soft seafloors. Prior techniques to increase anchorage capacity involve using larger single anchors, or using multiple anchors. These prior techniques can greatly complicate anchor installation and are often limited in application due to the availability of equipment to install larger anchors. Attempts to use conventional drag anchors in conjunction with stake piles to increase mooring capacity have been ineffective because the different anchor types have different load deformation characteristics and it is difficult or impractical to ensure that both anchors work together.
The present invention greatly increases the unidirectional holding capacity of pre-installed deadman-type anchors, and reduces load handling requirements while increasing anchor system capacity. In addition, the invention expands the utility of existing deadman-type anchors and can provide a capability where none presently exists, such as providing single anchor leg anchoring capability beyond the normal limits of an anchor. The invention increases anchor holding capacity without increasing installation complexity or the requirement for greater embedment energy. This anchor holding capacity augmentation system is especially suited for use in soft sediments where anchoring ability of conventional anchors is limited.